mm/nobootmem.c - SHIFTPHONES/mainline/linux - Gitiles

 /*
  *  bootmem - A boot-time physical memory allocator and configurator
  *
  *  Copyright (C) 1999 Ingo Molnar
  *                1999 Kanoj Sarcar, SGI
  *                2008 Johannes Weiner
  *
  * Access to this subsystem has to be serialized externally (which is true
  * for the boot process anyway).
  */
 #include <linux/init.h>
 #include <linux/pfn.h>
 #include <linux/slab.h>
 #include <linux/bootmem.h>
 #include <linux/export.h>
 #include <linux/kmemleak.h>
 #include <linux/range.h>
 #include <linux/memblock.h>

 #include <asm/bug.h>
 #include <asm/io.h>
 #include <asm/processor.h>

 #include "internal.h"

 #ifndef CONFIG_NEED_MULTIPLE_NODES
 struct pglist_data __refdata contig_page_data;
 EXPORT_SYMBOL(contig_page_data);
 #endif

 unsigned long max_low_pfn;
 unsigned long min_low_pfn;
 unsigned long max_pfn;

 static void * __init __alloc_memory_core_early(int nid, u64 size, u64 align,
 					u64 goal, u64 limit)
 {
 	void *ptr;
 	u64 addr;

 	if (limit > memblock.current_limit)
 		limit = memblock.current_limit;

 	addr = memblock_find_in_range_node(goal, limit, size, align, nid);
 	if (!addr)
 		return NULL;

 	memblock_reserve(addr, size);
 	ptr = phys_to_virt(addr);
 	memset(ptr, 0, size);
 	/*
 	 * The min_count is set to 0 so that bootmem allocated blocks
 	 * are never reported as leaks.
 	 */
 	kmemleak_alloc(ptr, size, 0, 0);
 	return ptr;
 }

 /*
  * free_bootmem_late - free bootmem pages directly to page allocator
  * @addr: starting address of the range
  * @size: size of the range in bytes
  *
  * This is only useful when the bootmem allocator has already been torn
  * down, but we are still initializing the system.  Pages are given directly
  * to the page allocator, no bootmem metadata is updated because it is gone.
  */
 void __init free_bootmem_late(unsigned long addr, unsigned long size)
 {
 	unsigned long cursor, end;

 	kmemleak_free_part(__va(addr), size);

 	cursor = PFN_UP(addr);
 	end = PFN_DOWN(addr + size);

 	for (; cursor < end; cursor++) {
 		__free_pages_bootmem(pfn_to_page(cursor), 0);
 		totalram_pages++;
 	}
 }

 static void __init __free_pages_memory(unsigned long start, unsigned long end)
 {
 	unsigned long i, start_aligned, end_aligned;
 	int order = ilog2(BITS_PER_LONG);

 	start_aligned = (start + (BITS_PER_LONG - 1)) & ~(BITS_PER_LONG - 1);
 	end_aligned = end & ~(BITS_PER_LONG - 1);

 	if (end_aligned <= start_aligned) {
 		for (i = start; i < end; i++)
 			__free_pages_bootmem(pfn_to_page(i), 0);

 		return;
 	}

 	for (i = start; i < start_aligned; i++)
 		__free_pages_bootmem(pfn_to_page(i), 0);

 	for (i = start_aligned; i < end_aligned; i += BITS_PER_LONG)
 		__free_pages_bootmem(pfn_to_page(i), order);

 	for (i = end_aligned; i < end; i++)
 		__free_pages_bootmem(pfn_to_page(i), 0);
 }

 static unsigned long __init __free_memory_core(phys_addr_t start,
 				 phys_addr_t end)
 {
 	unsigned long start_pfn = PFN_UP(start);
 	unsigned long end_pfn = min_t(unsigned long,
 				      PFN_DOWN(end), max_low_pfn);

 	if (start_pfn > end_pfn)
 		return 0;

 	__free_pages_memory(start_pfn, end_pfn);

 	return end_pfn - start_pfn;
 }

 static unsigned long __init free_low_memory_core_early(void)
 {
 	unsigned long count = 0;
 	phys_addr_t start, end, size;
 	u64 i;

 	for_each_free_mem_range(i, MAX_NUMNODES, &start, &end, NULL)
 		count += __free_memory_core(start, end);

 	/* free range that is used for reserved array if we allocate it */
 	size = get_allocated_memblock_reserved_regions_info(&start);
 	if (size)
 		count += __free_memory_core(start, start + size);

 	return count;
 }

 static int reset_managed_pages_done __initdata;

 static inline void __init reset_node_managed_pages(pg_data_t *pgdat)
 {
 	struct zone *z;

 	if (reset_managed_pages_done)
 		return;
 	for (z = pgdat->node_zones; z < pgdat->node_zones + MAX_NR_ZONES; z++)
 		z->managed_pages = 0;
 }

 void __init reset_all_zones_managed_pages(void)
 {
 	struct pglist_data *pgdat;

 	for_each_online_pgdat(pgdat)
 		reset_node_managed_pages(pgdat);
 	reset_managed_pages_done = 1;
 }

 /**
  * free_all_bootmem - release free pages to the buddy allocator
  *
  * Returns the number of pages actually released.
  */
 unsigned long __init free_all_bootmem(void)
 {
 	reset_all_zones_managed_pages();

 	/*
 	 * We need to use MAX_NUMNODES instead of NODE_DATA(0)->node_id
 	 *  because in some case like Node0 doesn't have RAM installed
 	 *  low ram will be on Node1
 	 */
 	return free_low_memory_core_early();
 }

 /**
  * free_bootmem_node - mark a page range as usable
  * @pgdat: node the range resides on
  * @physaddr: starting address of the range
  * @size: size of the range in bytes
  *
  * Partial pages will be considered reserved and left as they are.
  *
  * The range must reside completely on the specified node.
  */
 void __init free_bootmem_node(pg_data_t *pgdat, unsigned long physaddr,
 			      unsigned long size)
 {
 	kmemleak_free_part(__va(physaddr), size);
 	memblock_free(physaddr, size);
 }

 /**
  * free_bootmem - mark a page range as usable
  * @addr: starting address of the range
  * @size: size of the range in bytes
  *
  * Partial pages will be considered reserved and left as they are.
  *
  * The range must be contiguous but may span node boundaries.
  */
 void __init free_bootmem(unsigned long addr, unsigned long size)
 {
 	kmemleak_free_part(__va(addr), size);
 	memblock_free(addr, size);
 }

 static void * __init ___alloc_bootmem_nopanic(unsigned long size,
 					unsigned long align,
 					unsigned long goal,
 					unsigned long limit)
 {
 	void *ptr;

 	if (WARN_ON_ONCE(slab_is_available()))
 		return kzalloc(size, GFP_NOWAIT);

 restart:

 	ptr = __alloc_memory_core_early(MAX_NUMNODES, size, align, goal, limit);

 	if (ptr)
 		return ptr;

 	if (goal != 0) {
 		goal = 0;
 		goto restart;
 	}

 	return NULL;
 }

 /**
  * __alloc_bootmem_nopanic - allocate boot memory without panicking
  * @size: size of the request in bytes
  * @align: alignment of the region
  * @goal: preferred starting address of the region
  *
  * The goal is dropped if it can not be satisfied and the allocation will
  * fall back to memory below @goal.
  *
  * Allocation may happen on any node in the system.
  *
  * Returns NULL on failure.
  */
 void * __init __alloc_bootmem_nopanic(unsigned long size, unsigned long align,
 					unsigned long goal)
 {
 	unsigned long limit = -1UL;

 	return ___alloc_bootmem_nopanic(size, align, goal, limit);
 }

 static void * __init ___alloc_bootmem(unsigned long size, unsigned long align,
 					unsigned long goal, unsigned long limit)
 {
 	void *mem = ___alloc_bootmem_nopanic(size, align, goal, limit);

 	if (mem)
 		return mem;
 	/*
 	 * Whoops, we cannot satisfy the allocation request.
 	 */
 	printk(KERN_ALERT "bootmem alloc of %lu bytes failed!\n", size);
 	panic("Out of memory");
 	return NULL;
 }

 /**
  * __alloc_bootmem - allocate boot memory
  * @size: size of the request in bytes
  * @align: alignment of the region
  * @goal: preferred starting address of the region
  *
  * The goal is dropped if it can not be satisfied and the allocation will
  * fall back to memory below @goal.
  *
  * Allocation may happen on any node in the system.
  *
  * The function panics if the request can not be satisfied.
  */
 void * __init __alloc_bootmem(unsigned long size, unsigned long align,
 			      unsigned long goal)
 {
 	unsigned long limit = -1UL;

 	return ___alloc_bootmem(size, align, goal, limit);
 }

 void * __init ___alloc_bootmem_node_nopanic(pg_data_t *pgdat,
 						   unsigned long size,
 						   unsigned long align,
 						   unsigned long goal,
 						   unsigned long limit)
 {
 	void *ptr;

 again:
 	ptr = __alloc_memory_core_early(pgdat->node_id, size, align,
 					goal, limit);
 	if (ptr)
 		return ptr;

 	ptr = __alloc_memory_core_early(MAX_NUMNODES, size, align,
 					goal, limit);
 	if (ptr)
 		return ptr;

 	if (goal) {
 		goal = 0;
 		goto again;
 	}

 	return NULL;
 }

 void * __init __alloc_bootmem_node_nopanic(pg_data_t *pgdat, unsigned long size,
 				   unsigned long align, unsigned long goal)
 {
 	if (WARN_ON_ONCE(slab_is_available()))
 		return kzalloc_node(size, GFP_NOWAIT, pgdat->node_id);

 	return ___alloc_bootmem_node_nopanic(pgdat, size, align, goal, 0);
 }

 void * __init ___alloc_bootmem_node(pg_data_t *pgdat, unsigned long size,
 				    unsigned long align, unsigned long goal,
 				    unsigned long limit)
 {
 	void *ptr;

 	ptr = ___alloc_bootmem_node_nopanic(pgdat, size, align, goal, limit);
 	if (ptr)
 		return ptr;

 	printk(KERN_ALERT "bootmem alloc of %lu bytes failed!\n", size);
 	panic("Out of memory");
 	return NULL;
 }

 /**
  * __alloc_bootmem_node - allocate boot memory from a specific node
  * @pgdat: node to allocate from
  * @size: size of the request in bytes
  * @align: alignment of the region
  * @goal: preferred starting address of the region
  *
  * The goal is dropped if it can not be satisfied and the allocation will
  * fall back to memory below @goal.
  *
  * Allocation may fall back to any node in the system if the specified node
  * can not hold the requested memory.
  *
  * The function panics if the request can not be satisfied.
  */
 void * __init __alloc_bootmem_node(pg_data_t *pgdat, unsigned long size,
 				   unsigned long align, unsigned long goal)
 {
 	if (WARN_ON_ONCE(slab_is_available()))
 		return kzalloc_node(size, GFP_NOWAIT, pgdat->node_id);

 	return ___alloc_bootmem_node(pgdat, size, align, goal, 0);
 }

 void * __init __alloc_bootmem_node_high(pg_data_t *pgdat, unsigned long size,
 				   unsigned long align, unsigned long goal)
 {
 	return __alloc_bootmem_node(pgdat, size, align, goal);
 }

 #ifndef ARCH_LOW_ADDRESS_LIMIT
 #define ARCH_LOW_ADDRESS_LIMIT	0xffffffffUL
 #endif

 /**
  * __alloc_bootmem_low - allocate low boot memory
  * @size: size of the request in bytes
  * @align: alignment of the region
  * @goal: preferred starting address of the region
  *
  * The goal is dropped if it can not be satisfied and the allocation will
  * fall back to memory below @goal.
  *
  * Allocation may happen on any node in the system.
  *
  * The function panics if the request can not be satisfied.
  */
 void * __init __alloc_bootmem_low(unsigned long size, unsigned long align,
 				  unsigned long goal)
 {
 	return ___alloc_bootmem(size, align, goal, ARCH_LOW_ADDRESS_LIMIT);
 }

 void * __init __alloc_bootmem_low_nopanic(unsigned long size,
 					  unsigned long align,
 					  unsigned long goal)
 {
 	return ___alloc_bootmem_nopanic(size, align, goal,
 					ARCH_LOW_ADDRESS_LIMIT);
 }

 /**
  * __alloc_bootmem_low_node - allocate low boot memory from a specific node
  * @pgdat: node to allocate from
  * @size: size of the request in bytes
  * @align: alignment of the region
  * @goal: preferred starting address of the region
  *
  * The goal is dropped if it can not be satisfied and the allocation will
  * fall back to memory below @goal.
  *
  * Allocation may fall back to any node in the system if the specified node
  * can not hold the requested memory.
  *
  * The function panics if the request can not be satisfied.
  */
 void * __init __alloc_bootmem_low_node(pg_data_t *pgdat, unsigned long size,
 				       unsigned long align, unsigned long goal)
 {
 	if (WARN_ON_ONCE(slab_is_available()))
 		return kzalloc_node(size, GFP_NOWAIT, pgdat->node_id);

 	return ___alloc_bootmem_node(pgdat, size, align, goal,
 				     ARCH_LOW_ADDRESS_LIMIT);
 }
	/*
	* bootmem - A boot-time physical memory allocator and configurator
	*
	* Copyright (C) 1999 Ingo Molnar
	* 1999 Kanoj Sarcar, SGI
	* 2008 Johannes Weiner
	*
	* Access to this subsystem has to be serialized externally (which is true
	* for the boot process anyway).
	*/
	#include <linux/init.h>
	#include <linux/pfn.h>
	#include <linux/slab.h>
	#include <linux/bootmem.h>
	#include <linux/export.h>
	#include <linux/kmemleak.h>
	#include <linux/range.h>
	#include <linux/memblock.h>

	#include <asm/bug.h>
	#include <asm/io.h>
	#include <asm/processor.h>

	#include "internal.h"

	#ifndef CONFIG_NEED_MULTIPLE_NODES
	struct pglist_data __refdata contig_page_data;
	EXPORT_SYMBOL(contig_page_data);
	#endif

	unsigned long max_low_pfn;
	unsigned long min_low_pfn;
	unsigned long max_pfn;

	static void * __init __alloc_memory_core_early(int nid, u64 size, u64 align,
	u64 goal, u64 limit)
	{
	void *ptr;
	u64 addr;

	if (limit > memblock.current_limit)
	limit = memblock.current_limit;

	addr = memblock_find_in_range_node(goal, limit, size, align, nid);
	if (!addr)
	return NULL;

	memblock_reserve(addr, size);
	ptr = phys_to_virt(addr);
	memset(ptr, 0, size);
	/*
	* The min_count is set to 0 so that bootmem allocated blocks
	* are never reported as leaks.
	*/
	kmemleak_alloc(ptr, size, 0, 0);
	return ptr;
	}

	/*
	* free_bootmem_late - free bootmem pages directly to page allocator
	* @addr: starting address of the range
	* @size: size of the range in bytes
	*
	* This is only useful when the bootmem allocator has already been torn
	* down, but we are still initializing the system. Pages are given directly
	* to the page allocator, no bootmem metadata is updated because it is gone.
	*/
	void __init free_bootmem_late(unsigned long addr, unsigned long size)
	{
	unsigned long cursor, end;

	kmemleak_free_part(__va(addr), size);

	cursor = PFN_UP(addr);
	end = PFN_DOWN(addr + size);

	for (; cursor < end; cursor++) {
	__free_pages_bootmem(pfn_to_page(cursor), 0);
	totalram_pages++;
	}
	}

	static void __init __free_pages_memory(unsigned long start, unsigned long end)
	{
	unsigned long i, start_aligned, end_aligned;
	int order = ilog2(BITS_PER_LONG);

	start_aligned = (start + (BITS_PER_LONG - 1)) & ~(BITS_PER_LONG - 1);
	end_aligned = end & ~(BITS_PER_LONG - 1);

	if (end_aligned <= start_aligned) {
	for (i = start; i < end; i++)
	__free_pages_bootmem(pfn_to_page(i), 0);

	return;
	}

	for (i = start; i < start_aligned; i++)
	__free_pages_bootmem(pfn_to_page(i), 0);

	for (i = start_aligned; i < end_aligned; i += BITS_PER_LONG)
	__free_pages_bootmem(pfn_to_page(i), order);

	for (i = end_aligned; i < end; i++)
	__free_pages_bootmem(pfn_to_page(i), 0);
	}

	static unsigned long __init __free_memory_core(phys_addr_t start,
	phys_addr_t end)
	{
	unsigned long start_pfn = PFN_UP(start);
	unsigned long end_pfn = min_t(unsigned long,
	PFN_DOWN(end), max_low_pfn);

	if (start_pfn > end_pfn)
	return 0;

	__free_pages_memory(start_pfn, end_pfn);

	return end_pfn - start_pfn;
	}

	static unsigned long __init free_low_memory_core_early(void)
	{
	unsigned long count = 0;
	phys_addr_t start, end, size;
	u64 i;

	for_each_free_mem_range(i, MAX_NUMNODES, &start, &end, NULL)
	count += __free_memory_core(start, end);

	/* free range that is used for reserved array if we allocate it */
	size = get_allocated_memblock_reserved_regions_info(&start);
	if (size)
	count += __free_memory_core(start, start + size);

	return count;
	}

	static int reset_managed_pages_done __initdata;

	static inline void __init reset_node_managed_pages(pg_data_t *pgdat)
	{
	struct zone *z;

	if (reset_managed_pages_done)
	return;
	for (z = pgdat->node_zones; z < pgdat->node_zones + MAX_NR_ZONES; z++)
	z->managed_pages = 0;
	}

	void __init reset_all_zones_managed_pages(void)
	{
	struct pglist_data *pgdat;

	for_each_online_pgdat(pgdat)
	reset_node_managed_pages(pgdat);
	reset_managed_pages_done = 1;
	}

	/**
	* free_all_bootmem - release free pages to the buddy allocator
	*
	* Returns the number of pages actually released.
	*/
	unsigned long __init free_all_bootmem(void)
	{
	reset_all_zones_managed_pages();

	/*
	* We need to use MAX_NUMNODES instead of NODE_DATA(0)->node_id
	* because in some case like Node0 doesn't have RAM installed
	* low ram will be on Node1
	*/
	return free_low_memory_core_early();
	}

	/**
	* free_bootmem_node - mark a page range as usable
	* @pgdat: node the range resides on
	* @physaddr: starting address of the range
	* @size: size of the range in bytes
	*
	* Partial pages will be considered reserved and left as they are.
	*
	* The range must reside completely on the specified node.
	*/
	void __init free_bootmem_node(pg_data_t *pgdat, unsigned long physaddr,
	unsigned long size)
	{
	kmemleak_free_part(__va(physaddr), size);
	memblock_free(physaddr, size);
	}

	/**
	* free_bootmem - mark a page range as usable
	* @addr: starting address of the range
	* @size: size of the range in bytes
	*
	* Partial pages will be considered reserved and left as they are.
	*
	* The range must be contiguous but may span node boundaries.
	*/
	void __init free_bootmem(unsigned long addr, unsigned long size)
	{
	kmemleak_free_part(__va(addr), size);
	memblock_free(addr, size);
	}

	static void * __init ___alloc_bootmem_nopanic(unsigned long size,
	unsigned long align,
	unsigned long goal,
	unsigned long limit)
	{
	void *ptr;

	if (WARN_ON_ONCE(slab_is_available()))
	return kzalloc(size, GFP_NOWAIT);

	restart:

	ptr = __alloc_memory_core_early(MAX_NUMNODES, size, align, goal, limit);

	if (ptr)
	return ptr;

	if (goal != 0) {
	goal = 0;
	goto restart;
	}

	return NULL;
	}

	/**
	* __alloc_bootmem_nopanic - allocate boot memory without panicking
	* @size: size of the request in bytes
	* @align: alignment of the region
	* @goal: preferred starting address of the region
	*
	* The goal is dropped if it can not be satisfied and the allocation will
	* fall back to memory below @goal.
	*
	* Allocation may happen on any node in the system.
	*
	* Returns NULL on failure.
	*/
	void * __init __alloc_bootmem_nopanic(unsigned long size, unsigned long align,
	unsigned long goal)
	{
	unsigned long limit = -1UL;

	return ___alloc_bootmem_nopanic(size, align, goal, limit);
	}

	static void * __init ___alloc_bootmem(unsigned long size, unsigned long align,
	unsigned long goal, unsigned long limit)
	{
	void *mem = ___alloc_bootmem_nopanic(size, align, goal, limit);

	if (mem)
	return mem;
	/*
	* Whoops, we cannot satisfy the allocation request.
	*/
	printk(KERN_ALERT "bootmem alloc of %lu bytes failed!\n", size);
	panic("Out of memory");
	return NULL;
	}

	/**
	* __alloc_bootmem - allocate boot memory
	* @size: size of the request in bytes
	* @align: alignment of the region
	* @goal: preferred starting address of the region
	*
	* The goal is dropped if it can not be satisfied and the allocation will
	* fall back to memory below @goal.
	*
	* Allocation may happen on any node in the system.
	*
	* The function panics if the request can not be satisfied.
	*/
	void * __init __alloc_bootmem(unsigned long size, unsigned long align,
	unsigned long goal)
	{
	unsigned long limit = -1UL;

	return ___alloc_bootmem(size, align, goal, limit);
	}

	void * __init ___alloc_bootmem_node_nopanic(pg_data_t *pgdat,
	unsigned long size,
	unsigned long align,
	unsigned long goal,
	unsigned long limit)
	{
	void *ptr;

	again:
	ptr = __alloc_memory_core_early(pgdat->node_id, size, align,
	goal, limit);
	if (ptr)
	return ptr;

	ptr = __alloc_memory_core_early(MAX_NUMNODES, size, align,
	goal, limit);
	if (ptr)
	return ptr;

	if (goal) {
	goal = 0;
	goto again;
	}

	return NULL;
	}

	void * __init __alloc_bootmem_node_nopanic(pg_data_t *pgdat, unsigned long size,
	unsigned long align, unsigned long goal)
	{
	if (WARN_ON_ONCE(slab_is_available()))
	return kzalloc_node(size, GFP_NOWAIT, pgdat->node_id);

	return ___alloc_bootmem_node_nopanic(pgdat, size, align, goal, 0);
	}

	void * __init ___alloc_bootmem_node(pg_data_t *pgdat, unsigned long size,
	unsigned long align, unsigned long goal,
	unsigned long limit)
	{
	void *ptr;

	ptr = ___alloc_bootmem_node_nopanic(pgdat, size, align, goal, limit);
	if (ptr)
	return ptr;

	printk(KERN_ALERT "bootmem alloc of %lu bytes failed!\n", size);
	panic("Out of memory");
	return NULL;
	}

	/**
	* __alloc_bootmem_node - allocate boot memory from a specific node
	* @pgdat: node to allocate from
	* @size: size of the request in bytes
	* @align: alignment of the region
	* @goal: preferred starting address of the region
	*
	* The goal is dropped if it can not be satisfied and the allocation will
	* fall back to memory below @goal.
	*
	* Allocation may fall back to any node in the system if the specified node
	* can not hold the requested memory.
	*
	* The function panics if the request can not be satisfied.
	*/
	void * __init __alloc_bootmem_node(pg_data_t *pgdat, unsigned long size,
	unsigned long align, unsigned long goal)
	{
	if (WARN_ON_ONCE(slab_is_available()))
	return kzalloc_node(size, GFP_NOWAIT, pgdat->node_id);

	return ___alloc_bootmem_node(pgdat, size, align, goal, 0);
	}

	void * __init __alloc_bootmem_node_high(pg_data_t *pgdat, unsigned long size,
	unsigned long align, unsigned long goal)
	{
	return __alloc_bootmem_node(pgdat, size, align, goal);
	}

	#ifndef ARCH_LOW_ADDRESS_LIMIT
	#define ARCH_LOW_ADDRESS_LIMIT 0xffffffffUL
	#endif

	/**
	* __alloc_bootmem_low - allocate low boot memory
	* @size: size of the request in bytes
	* @align: alignment of the region
	* @goal: preferred starting address of the region
	*
	* The goal is dropped if it can not be satisfied and the allocation will
	* fall back to memory below @goal.
	*
	* Allocation may happen on any node in the system.
	*
	* The function panics if the request can not be satisfied.
	*/
	void * __init __alloc_bootmem_low(unsigned long size, unsigned long align,
	unsigned long goal)
	{
	return ___alloc_bootmem(size, align, goal, ARCH_LOW_ADDRESS_LIMIT);
	}

	void * __init __alloc_bootmem_low_nopanic(unsigned long size,
	unsigned long align,
	unsigned long goal)
	{
	return ___alloc_bootmem_nopanic(size, align, goal,
	ARCH_LOW_ADDRESS_LIMIT);
	}

	/**
	* __alloc_bootmem_low_node - allocate low boot memory from a specific node
	* @pgdat: node to allocate from
	* @size: size of the request in bytes
	* @align: alignment of the region
	* @goal: preferred starting address of the region
	*
	* The goal is dropped if it can not be satisfied and the allocation will
	* fall back to memory below @goal.
	*
	* Allocation may fall back to any node in the system if the specified node
	* can not hold the requested memory.
	*
	* The function panics if the request can not be satisfied.
	*/
	void * __init __alloc_bootmem_low_node(pg_data_t *pgdat, unsigned long size,
	unsigned long align, unsigned long goal)
	{
	if (WARN_ON_ONCE(slab_is_available()))
	return kzalloc_node(size, GFP_NOWAIT, pgdat->node_id);

	return ___alloc_bootmem_node(pgdat, size, align, goal,
	ARCH_LOW_ADDRESS_LIMIT);
	}